Flower-like S-doped-Ni2P mesoporous nanosheet-derived self-standing electrocatalytic electrode for boosting hydrogen evolution

Abstract

Developing cost-effective, highly active, and stable electrocatalysts for boosting electrochemical hydrogen evolution reaction (HER) in alkaline media is playing a critical role in meeting the demands of the hydrogen industry in the future. Herein, an efficient HER electrocatalyst based on flowerlike S-doped Ni2P mesoporous nanosheets (NSs) supported on nickel foam (S-Ni2P NSs/NF) was developed through an effective approach. The obtained S-Ni2P NSs/NF catalyst required low overpotential of only 87.5 and 179.1 mV to reach a current density of 10 and 50 mA cm−2, respectively. Moreover, a small Tafel slope of 62.1 mV dec−1 for S-Ni2P NSs/NF demonstrated that the HER process occurred with very fast kinetics. Besides high HER activity, the synthesized S-Ni2P NSs/NF catalyst exhibited superior stability and long-term durability towards HER, which had the ability to operate for over 30 h without degradation in catalytic performance. The unique flower-like nanosheet structure with excellent mesoporous characteristics of S-Ni2P NSs/NF resulted in maximizing the electrochemical active surface area for providing a large number of electrocatalytic active sites. In addition, the S-doping effect could modulate the electronic structure of Ni species in Ni2P, leading to an acceleration of the adsorption rate of reaction intermediates on the surface of catalysts towards improving HER kinetics. The results not only demonstrate S-Ni2P NSs/NF as an active catalyst for HER, but offer an effective strategy for improving the catalytic activity of earth-abundant transition metal-based HER catalysts.